How to JOIN a COUNT from a table, and then effect that COUNT with another JOIN

Question

I have three tables

Post

ID  Name
1   \'Something\'
2   \'Something else\'
3   \'One more\'

Comment

ID  PostId  Profile         


        

Answer 1

SELECT Post.Id, COUNT(Comment.ID) AS Count
FROM Post
LEFT JOIN Comment ON Comment.PostId = Post.ID
LEFT JOIN Profile ON Profile.ID = Comment.ProfileID
WHERE Profile.Approved = 1
GROUP BY Post.Id

Probably you didn't paste it for the sake of the example, but you might evaluate to de-normalize the Profile table together with the Comment one, by moving the Approved column in it.